DropWheel

A tiny macOS menu bar app for converting files in a flick. Hold Shift while dragging files and a wheel appears under your cursor. Drop onto a slice and the result is saved next to the original. Everything runs on your Mac: no internet, no uploads.

What it can do

The wheel only shows slices that fit what you're dragging:

You drag	Slices
Image	Convert → JPG · PNG · HEIC · WebP Rotate: 90° clockwise, in place (lossless for JPEG/HEIC) Crop → 1:1 · 4:5 · 16:9, centred on the subject Cut out: transparent PNG of just the subject Blur BG: portrait-mode style blurred background Shrink: max 2560px, JPEG 60%
Word / RTF / OpenDocument	PDF (no app opens, no windows)
PDF	Split into one file per page · Shrink
Video	MP4 · MP3 (audio only) · Shrink to 720p
Audio	MP3

Install

Requirements: macOS 14 (Sonoma) or newer and Homebrew.

1. Install Apple's developer tools (skip if you've done this before):

xcode-select --install

2. Install the optional helpers. ffmpeg enables WebP and MP3. LibreOffice keeps pictures when turning Word files into PDFs. DropWheel works without them; those features are just disabled or simpler.

brew install ffmpeg

brew install --cask libreoffice

3. Download and install DropWheel:

git clone https://github.com/Beqarev/DropWheel.git ~/DropWheel

~/DropWheel/build.sh install

This builds the app, puts it in /Applications, and starts it. A ◎ icon appears in your menu bar.

4. Allow folder access. On first start, macOS asks whether DropWheel may access your Desktop, Documents and Downloads folders. Click Allow each time, so it can save converted files next to the originals.

5. Start it automatically (optional): click the ◎ icon → Launch at Login.

How to use

1. Start dragging one or more files in Finder (or from your Desktop).
2. While dragging, hold Shift. The wheel appears under your cursor.
3. Move onto a slice and let go.
   • Convert and Crop open an outer ring: move onto the slice, then outward onto the choice (e.g. PNG).
   • Let go in the centre to cancel.
4. A green checkmark means it's done. The new file sits next to the original (photo.png, photo 1x1.jpg, photo cutout.png, …).

Only Rotate changes the original file. Everything else makes a new one and never overwrites anything.

Update

After pulling new code (or changing it yourself), reinstall:

cd ~/DropWheel && git pull && ./build.sh install

macOS may ask for folder access again after each install, because the app is signed locally rather than with an Apple Developer certificate.

Uninstall

Click the ◎ icon → Quit DropWheel, then delete /Applications/DropWheel.app.

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For developers

Built with Swift, SwiftUI and AppKit, using only Apple frameworks (ImageIO, AVFoundation, PDFKit, Vision, Core Image) plus the optional ffmpeg and LibreOffice. There's no Xcode project: swift build compiles it, and build.sh wraps it into an .app.

./build.sh run                         # build and launch from build/
build/DropWheel.app/Contents/MacOS/DropWheel --convert cutout photo.jpg   # test a conversion
build/DropWheel.app/Contents/MacOS/DropWheel --preview image 0 1          # show the wheel for 6 s

File	Role
main.swift	Starts the app as a menu bar app (no Dock icon).
AppDelegate.swift	Menu bar icon and menu; wires the drag monitor to the overlay.
DragMonitor.swift	Watches system-wide mouse drags. Fires when Shift is held and files are being dragged.
Overlay.swift	The floating frosted-glass window, and DropView, which receives the drop and works out which slice is under the cursor.
WheelView.swift	The wheel drawing (SwiftUI) plus the angle math.
WheelAction.swift	Every action, which file types it accepts, and how they group into slices. Add a new slice here.
Converter.swift	Format conversions, video/audio, PDF shrink/split.
ImageEdits.swift	Rotate, smart crop, cut out and blur background (Apple's Vision framework).
DocumentConverter.swift	Word → PDF (LibreOffice if installed, otherwise macOS's built-in reader, which skips pictures).
DevCommands.swift	Terminal test helpers.

No Accessibility permission needed. macOS lets any app observe global mouse events; only keyboard monitoring needs permission. DropWheel never watches the keyboard. It reads whether Shift is down at the moment the mouse drags.

Zero cost when idle. No timers or polling: macOS wakes the app only on mouse press or drag. It idles at 0% CPU and about 35 MB of memory.

Ideas

• Settings window: modifier key, JPEG quality, max size.
• Progress ring for long video exports.
• "Reveal in Finder" after converting.
• A real crop window with handles.
• PDF → Word (via LibreOffice) and GIF ↔ MP4.